The problem is how to combine two sessions of a pairs event which has different tops, an example being given with 18 pairs all-play-all, which has a 16 top followed by a 14 top.
All methods are legal.
EBU regs and current software require #1, which Max Bavin and Herman De Wael recommend.
The EBU Movements Manual by John Manning recommends #2. David Martin agrees for all-play-all. Max seems to think this might be acceptable if there is no computer available.
Both Max and John Manning disapprove of #3 and #4 [and presumable #5].
According to David Martin Haworth uses #1.
The Neuberg formula is [EBU version]
where M=actual MPs, E=largest no of scores on any board, A=actual no of scores on this board.
The ACBL version [based on half-match-points] is
which gets the same effective answers.
Herman recommends Ascherberg, which is not [as I was told by John Probst] a different method, but an all encompassing method that includes Neuberg but scores slightly differently.
It seems to me that all methods are legal, #2 is acceptable if there are no computers, but #1 seems best, and is used by EBU and Haworth software. OK?
Note that method #5 is definitely used and has the advantage that simple players prefer it as being clear and understandable. It presumably is equivalent to #3 or #4.